Braking device for automatic firearms



Jan. 21, 1941. w. c. ROEMr-:R

BRAKING DEVICE FOR AUTOMATIC FIREARMS Nn m mw @N .e s Q N mw mmmPatented Jan. 21, 1941 v I BBAKING DEVICE FOB AUTOMATIC FIBEARMS vWilliam C. Roemer, New Haven, Conn., assig'nor,

by menne, assignments, to Western Cartridge. Company, a corporation `ofDelaware Y Application August 2, 1938, Serial No. 222,589

Y I 5 Claims. This invention relates to a braking device for automaticfirearms of the recoil type, and more causing jamming orother'mal-functioning of theA firearm.

Another object of the present invention is to provide a superior brakingdevice for automatic firearms ofvsuch construction and arrangement ofparts as will permit the use of variable loads of shells to bedischarged in the said firearm and which will have a progressiveincrease in braking effect from minimum to maximum during the recoilmovement of the barrel-member of such With the above and other objectsin view, as will appear to those skilled in the art from the presentdisclosure, this invention includes all features in the said disclosurewhich are novel over the prior art. t

In the accompanying drawing, in which certain modes of carrying out thepresent invention are shown for illustrative purposes:

Fig. 1 is a broken view mainly in side elevation and partly in verticalcentral longitudinal section of an automatic shotgun embodying thepresent invention;

Fig. 2 is a similar view, but showing the barrelmember and associatedparts in the positions they assume when the barrel-member isintermediate its forward position and its fully-recoiled position;

Fig. 3 is a transverse sectional View taken on the line 3-3 of Fig. l; I1

Fig. 4 is a side elevational view of the magazine-tube, detached;

Fig. 5 is a transverse sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a perspective view of the split tion ring; and

Fig. 7 is a broken side elevational view of another form ofmagazine-tube.

The particular firearm herein chosen for illustration invFigs. 1 to 6inclusive is'in the form of an automatic shotgun and includes a barrelIU and a receiver II. Extending Vbeneath the barrel II) and rigidlysecured to the forward end of the fricreceiver I I is a magazine-tube I2theforward end of which passes through an axial passage I3 formed in theforward end of a forestock Il, the Vsaid forestock being supported atits forward end by the magazine-tube I2.' The forestock Il just referredto is retained in place upon the magazine-tube I2 against forward axialdisplacement relative to the said tube by means of a retaining-nut or-cap I5 threadedly secured to the, extreme forward end of themagazine-tube I2. vThe forestock I4 is also provided throughout themajor portion of its length with a longitudinal clearance-passage I3acoaxially arranged with the passage I3 and through which themagazine-tube I2 forwardly extends so as t'o be housed therein.

The barrel Ill is formed at its rear ,end with a barrel-extension I6which is adapted to reciprocate within the receiver II when the barrelIII moves axially for effecting the ejection of a red shell, thereloading of the rearm and the operation of a reciprocating breech-boltI1 visible through an ejection-opening I8 formed-in the side wall of thesaid receiver II. On its under side the barrel I is formed with abarrel-lug I9 preferably formed integral with the said barrel andextends downwardly into the clearancepassage 13a in the forestock I4.The barrel-lug I9 just referred to is provided with a bore 20 throughwhich the magazine-tube I2 freely extends. The said barrel-lug I9 isformed in its rear face coaxially with the bore 20 just referred to witha conical cam-surface 2l for the purpose as will hereinafter appear. i

The magazine-tube I2, intermediate its forward and rear ends, is formedwith an annular peripheral series of longitudinal grooves 22 (six, moreor less) which result in 'the formation of a corresponding series oflongitudinal ribs 23. The said grooves 22 and ribs 23 normally extendrearwardly of the barrel-lug I9, as is particularly well shown in Fig. lof the drawing.

Mounted on the magazine-tube I2 and rearwardly of the barrel-lug I9 is abarrel-return spring 24- having its rear end bearing against the forwardface of the receiver II and having its forward end bearing against therear face of an annular cam-ring 25. The said cam-ring 25 is mountedwith freedom for longitudinal movement upon the magazine-tube I2rearwardly of the barrel-lug I9. The barrel-return spring 24 thoughprimarily intended for .the purpose of returning the barrel III andassociatedparts to their normal forward position after the recoil of thesaid barrel, also serves as a yielding resistance for the purpose aswill hereinafter appear. The cam-ring 25 just referred to is provided inits forward face with a conical camsurface 26 complemental to theaforesaid camsurface 2| formed in the rear face of the barrellug I9.

Interposed between the barrel-lug I9 and the cam-ring 25 is a resilientsplit friction-ring 21 of bronze or other wear-resistant material andhaying its outer annular edges beveled as at 28-28 as is particularlywell shown in Figs. 1, 2 and 6. The friction-ring 21 is providedoppositely from its slot 29 with a longitudinal groove 30 which thinsthe wall of the frictionring 21 to a degree suilcient to form what mightbe termed a "hinge-portion 3|, for the purpose as will hereinafterappear.

As will be readily seen from the drawing, the friction-'ring 21 isadapted to be compressed upon the outer periphery of the tubularmagazine I2, by the cam-surfaces 2I and 26 respectively formed on thebarrel-lug I9 and the cam-ring 25. As shown in Fig. 1, the friction-ring21 is in a position near the forward end of the ribs 23 with the bevel28 at its forward end in constant engagement with the cam-surface 2l atthe rear face of the barrel-lug I9. At its rear end the friction-ring 21has its bevel 28 in constant engagement with the cam-surface 26 at theforward face of the cam-ring 25. The cam-ring 25 is held in engagementwith the friction-ring 21 by the return-spring 24 which also constantlyurges the cam-ring 25 and friction-ring 21 forwardly into engagementwith the barrel-lug I9.

In the relationship of the parts just above described, and asparticularly well shown in Fig. 1 of the drawing, the friction-ring 21is located near the forward end of what might be termed a minimumbraking zone indicated as at A in Fig. 4 of the drawing in which Vzonethe ribs 23 are located and in which the approximate minimum retardationrequired for the control of the recoil of the barrel I0 is provided.

A The discharge of the rearm will cause the barrel I0 to recoil in amanner well understood in the art for effecting the ejection of a redshell from the firing-chamber of the firearm, as wall as effecting thecocking oi the ring mechanism of the said firearm. The following forwardmovement of the barrel and breech-bolt will effect the insertion of anew shell fed from the magazine-tube I2 into the firing-chamber of thebarrel.

The recoil of the barrel I0 will cause the barrel-lug I9 forming partthereof to move rearwardly therewith together with the friction-ring 21and cam-ring 25 against the tension of the barrel-return spring 24. Thisrearward movement of the barrel I0, barrel-lug I9, frictionring 21 andcam-ring 25, is resisted by the barrelreturn spring 24 with the resultthat the frictionring 21 is amally pinched, so to speak, between thesaid barrel-lug I9 and the cam-ring 25 so that the cam-surfaces 2| and26 acting upon the bevels 28-28 will cause the frictionring 21 to becompressed upon the ribs 23 formed on the magazine I2 for frictionalengagement therewith. This compression of the friction-ring 21 isgreatly facilitated by the hinge-portion 3I formed oppositely from theslot 29 in the said ring. Thesaid hinge-portion 3l permits thefriction-ring 21 to respond to the slightest change of pressure createdbetween the barrel-lug I9 and the cam-ring 25 by the recoil of thebarrel I0.

The recoil of the barrel I0 together with the barrel-lug I9,friction-ring 21, cam-ring 25, ultimately moves the parts just referredto rearwardly to a position slightly beyond that shown in Fig. 2 of thedrawing. As shown in the figure just referred to, the friction-ring 21has entered the maximum braking zone indicated at B in Fig. 4

of the drawing directly to the rear of the zone A, which former zone, itwill be noted, consists of the entire outer peripheral surface of themagazine-tube l2. The said zone B therefore presents a greaterfrictional area to offer resistance to the rearward travel of thefriction-ring 21 as compared to the relatively-small frictional areaoffered by the faces 32 of the ribs 23 in the zone of minimum brakingeffect marked A.

It will be understood that as the barrel recoils, the further therearward movement of the barrellug I9, friction-ring 21 and cam-ring 25,the greater the resistance offered by the barrel-return spring 24 andconsequently the greater the compression of the friction-ring 21 by thecam-surfaces 2I and 26 upon the periphery of the magazine I2. As thecompression of the friction-ring 21 increases during the rearward travelthereof,

the greater will be the frictional resistance created between the innerannular surface of the said friction-ring 21 and the ribs 23. The effectY of the friction-ring 21 entering the zone B of maximum braking is thatof cushioning the recoil of the barrel I 0 with a resultant sharpdecrease in the rearward travel thereof thus avoiding undue impacting ofthe barrel-extension I 6 against the rear wall of the receiver II.

Fig. 'l illustrates a modified form of magazinetube 33 that may beemployed in place of the magazine-tube I2 or its equivalent illustratedin Figs. 1 to 6 inclusive. As shown, the magazinetube 33 is essentiallythe same in all characteristics as the magazine-tube I2, save that thesaid magazine-tube 33 is formed intermediate its forward and rear endswith a peripheral annular series of rearwardly and inwardly taperinggrooves or recesses 34 which result in the formation of a correspondingseries of rearwardly-andoutwardly-tapering ribs 35. The tapered ribs 35form a minimum braking zone C corresponding generally to the zone A onthe magazine-tube I2 employed in the structure shown in Figs. 1 to 6,inclusive.

'I'he zone C, above referred to, differs from the zone A of thestructure of Figs.A 1 to 6 inclusive in that the ribs 35 of the zone Coffer minimum resistance to a friction-ring at their forward ends 36 toa friction-ring like the aforesaid frictionring 21, the said ribs 35broadening as they progress rearwardly which results in an increase ofsurface-area as at 31 merging into a maximum braking zone Dcorresponding to the zone B on 4the magazine-tube l2 employed in theconstruction previously described.

The zone C corresponds in function to the zone A for controlling therecoil of the barrel ,I0 in a manner similar to that described inconnection with the braking device illustrated and described in Figs. 1to 6 inclusive, save that the braking of the recoil of the said barrelis progressively increased from minimum braking to maximum brakingduring the course of its rearward travel.

It will be apparent that a frictio -ring initially located at theforward end of the zone C at the beginning of the recoil movement willhave its inner annular surface engaged with the relatively-narrow ends36 of the ribs 35 which offer a minimum amount of friction-surface area.friction-ring, during the period of its travel from Thefront to rear ofthe zone C will be frictionally engaged by an increasing surface areadue to the outward-tapering of the ribs `35, with the result that thefriction-ring and hence the barrel I0, will be retarded withprogressively increasing braking-action as the recoil movementcontinues. The friction-ring. upon passing over the area 31 formed atthe rear ends of the ribs 35 passes into the maximum braking zone DWhere the maximum frictional surface engages the inner annular surfaceof the friction-ring for cushioning the recoil of the barrel It, thuspreventing the barrel-extension formed at the rear of the said barrelfrom striking the rear wall of the receiver with any harmfully sharpblow which might result in damage to the working mechanism of thefirearm.

From the foregoing, it will be readily seen that provision has been madefor the gradual retarding of the recoil of the barrel of the firearm,and that in both forms of the invention illustrated in the drawing theminimum braking effect takes place at the beginning of the recoil strokeof the barrel. By having the minimum braking effect at the beginning ofthe recoil of the said barrel,

the operations of breaking loose of the fired shell from thefiring-chamber of the firearm, and ejecting a fired shell may be quicklyinitiated and these operations, and cooking of the firing mechanism maybe readily accomplished. After the barrel enters the zone of maximumbraking the said barrel is prevented from too sharply striking the rearw-all of the receiver Il. It will thus be seen that shells having eitherheavy or light loads may be interchangeably employed at will withoutcausing a failurein the operation of the firearm or undue shock thereto.

The invention may be carried out in other speciflc ways than thoseherein set forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

I claim: v

1. An automatic firearm construction including in combination: areceiver; a barrel reciprocatable with respect to the said receiver; atube extending substantially parallel with the said barrel and providedupon its exterior periphery with longitudinally-extending alternatingtapered grooves and tapered ribs, the said grooves having their widestportions located forwardly with respect to the said barrel and the saidribs having their widest portions located rearwardly with respect to thesaid barrel; and a friction-member movable rearwardly by the said barrelfrom the narrower portion of the tapered ribs on the said tube to thewider rear portions of the said ribs for frictionally checking therearward travel of the said barrel.

42. An automatic firearm construction including in combination: areceiver; a barrel reciprocable with respect to the said receiver; acartridge-receiving magazine-tube xedly connected to the s-aid receiverand having its periphery provided with a 'forward friction-surface ofrelatively-small frictional area per unit of length, and a rearwardfriction-surface of relatively-greater frictional area per same unit oflength; and a contractibie friction-means contractibie against andslidable along said forward and rearward friction-surfaces duringreciprocatory movement of the said barrel, substantially all portions ofthe said friction-surfaces along any line engaged by a given portion ofsaid contractibie frictionmeans during sliding movement of saidcontractible friction-means, being at a substantially uniform distancefrom the longitudinal axis of said magazine-tube.

3. An automatic rearm construction including in combination: a receiver;a barrel reciprocable with respect to the said receiver; acartridge-receiving magazine-tube xedly connected to the said receiverand having its periphery provided with a forward friction-surface ofrelatively-small frictional area per unit of length and consisting ofribs, and a rearward friction-surface of relatively-greater frictionalarea per same unit of length; and a contractibie friction-meanscon-tractible against and slidable along said forward and rearwardfriction-surfaces during reciprocatory movement of the said barrel,substantially all portions of the said friction-surfaces along any lineengaged by a given portion of said contractibie friction-means duringsliding movement of said contractibie friction-means, being at asubstantially uniform distance from the longitudinal axis of saidmagazine-tube.

4. An automatic firearm construction including in combination: areceiver; a barrel reciprocable with respect to the said receiver; acylindrical cartridge-receiving magazine-tube xedly connected to thesaid receiver and having its periphery provided with a forwardfriction-surface of relatively-small frictional area per unit of length.and a rearward friction-surface of relatively-greater frictional areaper same unit of length; and a contractibie friction-means contractibieagainst and slidable along said. forward land rearward friction-surfacesduring reciprocatory movement of the said barrel.

5. An automatic firearm construction including in combination: areceiver; a barrel reciprocable with respect'to the said receiver; acylindrical cartridge-receiving magazine-tube xedly connected to thesaid receiver and having its periphery provided witha forwardfriction-surface of relatively-small frictional area per unit of lengthand consisting of ribs, and a rearward friction-surface ofrelatively-greater frlctional area per same unit of length; and acontractibie friction-means contractibie against and slidable along saidforward and rearward friction-surfaces during' reciprocatory movement ofthe said barrel.

